Cable insulation and shielding defect detection system and method

Abstract

The invention provides a cable insulation and shielding defect detection system and method, a heating device is used for heating a target object, an imaging device comprises a microscope and a light emitting part, the light emitting part is used for projecting light to the target object heated to a preset state, and the microscope is used for obtaining image information of the target object; the image information is used for analyzing defect data of the target object. According to the cable insulation and shielding defect detection system and method, the high-precision image of the cable sample can be obtained under the cooperation of the microscope and the strong light source, so that the defect can be identified more accurately. Not only can defects in cable insulation be detected, but also semiconductive and insulation interfaces can be analyzed in detail. Through the fixing device, the cable sample can be rotated in the detection process, and the microstructure defects of the cable sample can be observed more comprehensively. The method is of great significance in improving the quality and the reliability of the cable, so that powerful technical support is provided for manufacturing and maintenance of the cable.

Description

Technical Field

[0001] This application relates to the field of cable technology, and in particular to systems and methods for detecting defects in cable insulation and shielding. Background Technology

[0002] In the process of cable manufacturing and maintenance, detecting defects in cable insulation is crucial. Traditional inspection methods, such as visual inspection and manual measurement, may not be able to fully or accurately identify all types of defects.

[0003] For example, inherent defects such as material inhomogeneity, contaminants such as impurities introduced during manufacturing, and insulation degradation caused by partial discharge, such as electrical trees or water trees, can all adversely affect the performance and lifespan of cables. Furthermore, air gaps or inhomogeneities at the interface between the semiconductor and insulation in the cable can lead to electric field distortion, resulting in partial discharge, inducing the growth of electrical trees or water trees, and ultimately causing cable breakdown. Summary of the Invention

[0004] Therefore, it is necessary to provide a cable insulation and shielding defect detection system and method to address the aforementioned technical problem of the inability to fully or accurately identify defects.

[0005] This application provides a cable insulation and shielding defect detection system, the cable insulation and shielding defect detection system comprising:

[0006] A heating device configured to heat a target object;

[0007] An imaging device, comprising a microscope and a light-emitting element, the light-emitting element being configured to project light onto a target object heated to a preset state, the microscope being configured to acquire image information of the target object, and the image information being configured to analyze defect data of the target object.

[0008] In one embodiment, the heating device includes:

[0009] A heating container having a heating chamber configured at least for holding a heat-conducting liquid;

[0010] A heating device, which is assembled in the heating container and configured to heat a heat-conducting liquid located in the heating chamber.

[0011] In one embodiment, the heat-conducting fluid is configured as an oil; and / or,

[0012] At least a portion of the heating container is configured as a transparent structure.

[0013] In one embodiment, the cable insulation and shielding defect detection system includes:

[0014] A fixing device includes a device base, a moving mechanism, and a clamping mechanism. The moving mechanism is mounted on the fixing device, and the clamping mechanism is mounted at the end of the moving mechanism. The moving mechanism is configured to control the movement of the clamping mechanism in three-dimensional space, and the clamping mechanism is configured to clamp and fix a target object.

[0015] In one embodiment, the cable insulation and shielding defect detection system includes:

[0016] An analysis device configured to analyze defect data of a target object based on the image information.

[0017] In one embodiment, the target object is configured as a cable sample; and / or,

[0018] The target object is configured as cross-linked polyethylene insulation material.

[0019] This application provides a method for detecting defects in cable insulation and shielding, the method comprising the following steps:

[0020] The heating cable sample caused the crystalline components in the cable sample to completely melt.

[0021] Light is projected onto the heated cable sample to obtain image information of the cable sample;

[0022] The defect data of the cable sample are analyzed based on the image information.

[0023] In one embodiment, the steps of the heating cable sample include:

[0024] Immerse the cable sample in oil preheated to above 100°C and continue heating until the crystalline components in the cable sample are completely melted.

[0025] In one embodiment, the steps of the heating cable sample include:

[0026] Immerse the cable sample in oil preheated to 120℃-180℃ and continue heating for more than half an hour.

[0027] In one embodiment, prior to implementing the heating cable sample, the following steps are included:

[0028] Degas the cable sample;

[0029] Remove the semi-conductive outer insulation shielding layer of the cable sample, retain the insulation layer of the cable sample, and obtain the insulated wire core of the cable sample;

[0030] Polish the surface of the insulating layer and the edge cuts of the semi-conductive outer insulating shielding layer until they are smooth;

[0031] The insulated wire core is wiped clean after being stripped, cut, and polished to remove the powder generated on the surface of the insulated wire core during polishing.

[0032] The aforementioned cable insulation and shielding defect detection system and method, with the aid of a microscope and a powerful light source, can obtain high-precision images of cable samples, thereby more accurately identifying defects. It can not only detect defects in cable insulation but also perform detailed analysis of the semiconducting and insulating interfaces. A fixing device allows for rotation of the cable sample during the detection process, enabling a more comprehensive observation of the microstructural defects. This is of great significance for improving cable quality and reliability. Through panoramic high-precision analysis, defects in cable insulation can be better identified and analyzed, thus providing strong technical support for cable manufacturing and maintenance. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a cable insulation and shielding defect detection system provided in one embodiment of this application.

[0034] Figure 2 An interface analysis table for a cable insulation and shielding defect detection system provided in one embodiment of this application.

[0035] Icon labels:

[0036] 100. Target object;

[0037] 1000. Heating device; 2000. Imaging device; 3000. Fixing device; 4000. Analytical device;

[0038] 1100. Heating container; 1200. Heating device;

[0039] 2100. Microscope; 2200. Light-emitting components;

[0040] 3100, base; 3200, moving mechanism; 3300, clamping mechanism. Detailed Implementation

[0041] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0042] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0043] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0045] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0047] See Figure 1 As shown, this application provides a cable insulation and shielding defect detection system, which includes a heating device 1000 and an imaging device 2000. The heating device 1000 is configured to heat a target object 100. The imaging device 2000 includes a microscope 2100 and a light-emitting element 2200. The light-emitting element 2200 is configured to project light onto the target object 100 heated to a preset state. The microscope 2100 is configured to acquire image information of the target object 100, and the image information is configured to analyze defect data of the target object 100. The target object 100 is configured to be cross-linked polyethylene insulation material, meaning that defect detection is mainly performed on cables with cross-linked polyethylene insulation material. In one embodiment, the target object 100 is configured as a cable sample, which is a cable segment without conductors.

[0048] For example, firstly, cables of different sizes are selected as cable samples. The preferred length of the cable samples is 20cm ≥ L ≥ 5cm. The outer shield of the cable samples is ground down to remove the outer shielding layer. When conducting interface defect detection on the cable insulation cores at different extrusion locations, if the extruded length of the cable insulation core is <100 meters, samples from both ends are taken as cable samples. If the extruded length of the cable insulation core is ≥200 meters, samples from both ends and every 100 meters are taken as cable samples, and tests are conducted accordingly. The length of the cable samples to be tested can be limited to L ≤ 10cm.

[0049] In one embodiment, the semi-conductive outer insulation shielding layer of the degassed cable sample can be removed. A cable shielding stripper is then used to spirally cut away the insulation shielding along the cable axis. The stripping thickness is determined based on the nominal thickness of the insulation shielding, aiming to minimize damage to the insulation layer. The insulation surface and the cut edges of the insulation shielding are then smoothed using sandpaper of different mesh sizes. The stripped and polished insulation core is then cleaned with anhydrous ethanol to remove shielding and insulation powder generated during polishing. After all the residual anhydrous ethanol on the surface of the insulation core has evaporated, the cable sample is obtained.

[0050] In one embodiment, the heating device 1000 includes a heating container 1100 and a heating element 1200. The heating container 1100 has a heating chamber configured to hold a heat-conducting liquid. The heating element 1200 is mounted to the heating container 1100 and configured to heat the heat-conducting liquid located in the heating chamber. The heating element 1200 can be connected to a matching temperature control device to control the degree of heating of the heating element 1200.

[0051] In one embodiment, the heat-conducting liquid is configured as an oil, and at least a portion of the heating container 1100 is configured as a transparent structure, such as a transparent test chamber, to facilitate observation. Therefore, the cable sample can be heated in an oil bath using the heating device 1000 described above, causing the crystalline components in the cross-linked polyethylene insulation material to melt, thereby making the cable sample irregular and transparent, facilitating observation by the microscope 2100.

[0052] The microscope 2100 of the imaging device 2000 can be a stereo microscope 2100. By using a stand to tilt the stereo microscope 2100, the cable sample can be observed from the side, and high-precision imaging of the heated cable sample can be performed. The light-emitting element 2200 of the imaging device 2000 can be a powerful light source. The powerful light source is used in conjunction with the microscope 2100 to provide sufficient illumination to obtain clear images of the cable sample.

[0053] In one embodiment, the cable insulation and shielding defect detection system includes a fixing device 3000, which comprises a device base 3100, a moving mechanism 3200, and a clamping mechanism 3300. The moving mechanism 3200 is mounted on the fixing device 3000, and the clamping mechanism 3300 is mounted at the end of the moving mechanism 3200. The moving mechanism 3200 is configured to control the movement of the clamping mechanism 3300 in three-dimensional space, and the clamping mechanism 3300 is configured to clamp and fix the target object 100. The moving mechanism 3200 may employ a multi-axis motion system, and the clamping mechanism 3300 can meet the clamping requirements of cable samples of different cable sizes. The multi-axis motion system can move the cable sample in three or four dimensions, thereby imaging the microstructure of the cable insulation layer and interface layer from all directions.

[0054] In one embodiment, the cable insulation and shielding defect detection system includes an analysis device 4000 configured to analyze defect data of a target object 100 based on image information. Therefore, a cable sample can be heat-treated using a heating device 1000 by immersing the sample in a heated oil bath at 120°C-180°C for half an hour. The heated cable insulation layer and insulation / shielding interface layer sample are imaged using a microscope 2100 and a high-power light source to detect defects in the insulation, such as inherent defects, contaminants, electrical trees, or water trees. The analysis device 4000 can then perform interface analysis, analyzing the semiconducting and insulating interfaces to investigate protrusions, contaminants, scratches, or other quality defects.

[0055] For example, the nominal inner diameter r of the cable conductor shield. The observed image size S = L × 2πr. When analyzing high-precision images, digital image processing is used to classify and statistically analyze the sizes of the conductor shield protrusions.

[0056] like Figure 2 As shown, there are n1 particles with a diameter (D) > 50 μm, n2 particles with a diameter (D) > 80 μm, and n3 particles with a diameter (D) > 125 μm. Alternatively, there are n1 particles with a diameter (D) > 50 μm, n2 particles with a diameter (D) > 100 μm, and n3 particles with a diameter (D) > 300 μm. The protruding particles are categorized and counted according to different voltage levels. If the number of protruding particles exceeds the requirement for that voltage level, the cable product does not meet the usage requirements.

[0057] The performance of the cable interface was evaluated by statistically analyzing the diameters of the insulation micropores using digital image processing, and calculating the total defect area S. D =π(D 微孔1 / 2) 2 +π(D 微孔2 / 2) 2 +π(D 微孔n / 2) 2 The total length S of the test samples is obtained by summing the test results of all the test samples. D ’ =S D首端 +S D尾端 +···+S Dn The total observed image size S of the test samples ’ =S 首端 +S 尾端 +···+S n .

[0058] Evaluation coefficient P for micropore defects at the cable insulation and shielding interface, P=S D ’ / S ’*100%. The evaluation coefficient P for micropore defects at the insulation and shielding interface of different cables is evaluated.

[0059] Based on the aforementioned detection methods, high-precision images of cable samples can be obtained with the aid of a microscope 2100 and a powerful light source, enabling more accurate defect identification. It can detect not only defects in cable insulation but also perform detailed analysis of the semiconducting and insulating interfaces. The fixing device 3000 allows for rotation of the cable sample during inspection, providing a more comprehensive observation of microstructural defects. This is of great significance for improving cable quality and reliability. Through panoramic high-precision analysis, defects in cable insulation can be better identified and analyzed, thus providing strong technical support for cable manufacturing and maintenance.

[0060] Cable sample sections are mounted on a multi-axis motion system sample stage. A hot oil bath within a transparent test chamber controls the silicone oil temperature (T≥120℃) using a temperature control device. The cable sample is placed in the hot oil bath via the multi-axis motion system sample stage and kept at a constant temperature (t≥30min). Using a stereomicroscope 2100 and a high-power light source, the internal porosity of the cable sample insulation, as well as protrusions and micropores at the insulation-inner shield interface, are detected. The size and number of protrusions and micropores are recorded to evaluate the performance of the cable insulation-shielding interface. This invention enables rapid evaluation of the insulation-shielding interface performance of XLPE cables, significantly improving the evaluation of cable interface performance and reducing testing costs.

[0061] This application provides a method for detecting defects in cable insulation and shielding, which includes the following steps:

[0062] The process involves heating a cable sample to completely melt the crystalline components within it; projecting light onto the heated cable sample to acquire image information; and analyzing the defect data of the cable sample based on the image information. In one embodiment, the heating step includes immersing the cable sample in oil preheated to above 100°C and continuing heating until the crystalline components in the cable sample are completely melted. In another embodiment, the heating step includes immersing the cable sample in oil preheated to 120°C-180°C and continuing heating for at least half an hour.

[0063] In one embodiment, prior to implementing the heating cable sample step, the following steps are included:

[0064] The cable sample is degassed; the semi-conductive outer insulation shielding layer of the cable sample is removed, while the insulation layer of the cable sample is retained, resulting in the insulated core of the cable sample; the surface of the insulation layer and the edge cut of the semi-conductive outer insulation shielding layer are polished to a smooth state; the insulated core after stripping and polishing is wiped clean to remove the powder generated on the surface of the insulated core during polishing.

[0065] Therefore, in one specific embodiment, the degassed cable sample can first be fixed, and its semi-conductive outer insulation shielding layer removed. The cable sample is then immersed in a hot oil bath preheated to 140°C and heated continuously until the crystalline components in the cross-linked polyethylene insulation material are completely melted. The heated cable sample is then moved to the observation position of microscope 2100, and the focal length and light source intensity of microscope 2100 are adjusted to obtain a high-resolution image of the cable sample. Various defects in the cable insulation are analyzed using the images obtained by microscope 2100, and the analysis results are recorded.

[0066] Continue reading Figure 2 As shown, for example, analyzing the size and number of protrusions at the interface, there are n1 particles with D > 50 μm, n2 particles with D > 80 μm, and n3 particles with D > 125 μm. The protruding particles are classified and statistically analyzed according to different voltage levels. If the number of protruding particles exceeds the requirements for that voltage level, the cable product does not meet the usage requirements. Finally, the size and number of micropore defects at the interface are analyzed, and the evaluation coefficient P for micropore defects at the cable insulation and shielding interface is calculated.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A cable insulation and shielding defect detection system, characterized in that, The cable insulation and shielding defect detection system includes: A heating device (1000) is configured to heat a target object (100). An imaging device (2000) includes a microscope (2100) and a light-emitting element (2200), the light-emitting element (2200) being configured to project light onto a target object (100) heated to a preset state, the microscope (2100) being configured to acquire image information of the target object (100), the image information being configured to analyze defect data of the target object (100).

2. The cable insulation and shielding defect detection system according to claim 1, characterized in that, The heating device (1000) includes: A heating container (1100) having a heating chamber configured at least for holding a heat-conducting liquid; A heating element (1200) is mounted on the heating container (1100) and is configured to heat a heat-conducting liquid located in the heating chamber.

3. The cable insulation and shielding defect detection system according to claim 2, characterized in that, The heat-conducting fluid is configured as an oil; and / or, At least a portion of the heating container (1100) is configured as a transparent structure.

4. The cable insulation and shielding defect detection system according to claim 1, characterized in that, The cable insulation and shielding defect detection system includes: A fixing device (3000) includes a device base (3100), a moving mechanism (3200), and a clamping mechanism (3300). The moving mechanism (3200) is mounted on the fixing device (3000), and the clamping mechanism (3300) is mounted at the end of the moving mechanism (3200). The moving mechanism (3200) is configured to control the movement of the clamping mechanism (3300) in three-dimensional space, and the clamping mechanism (3300) is configured to clamp and fix a target object (100).

5. The cable insulation and shielding defect detection system according to claim 1, characterized in that, The cable insulation and shielding defect detection system includes: An analysis device (4000) is configured to analyze defect data of a target object (100) based on the image information.

6. The cable insulation and shielding defect detection system according to claim 1, characterized in that, The target object (100) is configured as a cable sample; and / or, The target object (100) is configured as a cross-linked polyethylene insulation material.

7. A method for detecting defects in cable insulation and shielding, characterized in that, The cable insulation and shielding defect detection method includes the following steps: The heating cable sample caused the crystalline components in the cable sample to completely melt. Light is projected onto the heated cable sample to obtain image information of the cable sample; The defect data of the cable sample are analyzed based on the image information.

8. The cable insulation and shielding defect detection method according to claim 7, characterized in that, The steps for obtaining the heating cable sample include: Immerse the cable sample in oil preheated to above 100°C and continue heating until the crystalline components in the cable sample are completely melted.

9. The cable insulation and shielding defect detection method according to claim 8, characterized in that, The steps for obtaining the heating cable sample include: Immerse the cable sample in oil preheated to 120℃-180℃ and continue heating for more than half an hour.

10. The cable insulation and shielding defect detection method according to claim 7, characterized in that, Before implementing the steps described in the heating cable sample, the following steps are included: Degas the cable sample; Remove the semi-conductive outer insulation shielding layer of the cable sample, retain the insulation layer of the cable sample, and obtain the insulated wire core of the cable sample; Polish the surface of the insulating layer and the edge cuts of the semi-conductive outer insulating shielding layer until they are smooth; The insulated wire core is wiped clean after being stripped, cut, and polished to remove the powder generated on the surface of the insulated wire core during polishing.

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